Clam shell gate action

ABSTRACT

In a concrete placing bucket at the bottom of which is a chute is a pair of clam shell gates pivotally mounted on the bucket so that they can be simultaneously swung outwardly to open the chute and release the contents of the bucket. To open the gates a handle is swung downwardly by hand and an actuator arm and synchronizer link mechanism multiplies the manual force to swing the gates open. Two actuator arms are pivotally attached together and when moved downwardly pull upper ends of the gates toward each other to swing lower ends of the gates away from each other. A synchronizer link attached to one gate above the pivot point and to the other gate below the pivot point forces the gates to move at approximately equal rates over approximately equal opening distances.

United States Patent 1191 Garlinghouse 1541 CLAM SHELL GATE ACTION [75] inventor: Leslie ll. Garllnghouse, Pasadena,

Calif.

[73] Assignee: Garlinghouse Brothers, Los Angeles, Calif.

[22] Filed: Dec. 7, 1971 21 Appl. No.: 205,511

[52]. US. Cl. ..294/71, 294/69 R [51] Int. Cl. ..B66c 3/00, E21b 33/132 [58] Field of Search..294/68, 69, 70, 71; 37/183 AR,

[56] References Cited UNITED STATES PATENTS 543,182 7/1895 Hant ...222/503 3,521,925 7/1970 Heal ..294/71 2,812,970 1 1/1957 Martinson ..222/503 Feb. 13, 1973 Primary Examiner-Harvey C. l-lomsby Attorney-Vemon D. Beehler et a1.

[ ABSTRACT In a concrete placing bucket at the bottom of which is a chute is a pair of clam shell gates pivotally mounted on the bucket so that they can be simultaneousiy swung outwardly to open the chute and release the contents of the bucket. To open the gates a handle is swung downwardly by hand and an actuator arm and synchronizer link mechanism multiplies the manual 7 force to swing the gates open. Two actuator arms are pivotally attached together and when other to swing lower ends of the gates away from each other. A synchronizer link attached to one gate above the pivot point and to the other gate below the pivot point forces the gates to move at approximately equal rates over approximately equal opening distances.

12 Claims, 9 Drawing Figures moved downwardly pull upper ends of the gates toward each PATENTEDFmmm 716 SHEET 2 05 3 JNVEN role 15:4 EH Gamma/ 00x5 1 3 35 107- ram/Eda C LAM SHELL GATE ACTION Prior art patents in this field are U.S. Pat. Nos. 3,104,125 and 2,713,507.

Buckets for placing concrete in forms which are possessed of a handle to be suspended from a hoist of some kind have been in common use for a considerable period of time. The buckets referred to are, in terms of the trade, relatively large varying in capacity from onefourth to one-half cubic yard up to sizes cubic yards and greater. In a great many buckets of this kind clam shell gates are employed which close a chuteat the bottomof the bucket and which can be opened either partially for distributing modest quantities of the concrete contents of the bucket and then closed while the bucket is being shifted to a different location or on other occasions may be swung to a wide open position when the entire contents of the bucket are to be deposited at one time.

In some of the smaller sizes the clam shell gates are swung between open and closed positions manually, there being provided a handle of sufficient length to be moved with a sufficient mechanical advantage to exercise considerable pressure for a swinging movement of the gates. In the larger buckets hydraulic cylinders or other mechanical aids have been used for moving the gates between open and closed positions. The greatest amount of power is needed for cracking the gates from a full closed to a partially open position inasmuch as at this stage of the operation the entire weight of the bucket contents are resting on the gate providing greatest resistance to the opening swing. A considerable amountof power is also needed to close the gates from a partially open position when the flow of contents is to be stopped while the bucket is shifted from one location to another.

A simple conventional linkage has been heretofore used for causing both gates to operate simultaneously when the handle is manipulated so that they swing away from each other when opening and toward each other when closing. It has also been necessary to supply some mechanical expedient to be certain that the gates do move simultaneously. Such devices as have heretofore been employed, while successful in performing the operation, have required a considerable amount of power making a special linkage necessary when manipulated by hand or on the other hand making some power actuatedopener necessary for sizes too heavy for manual manipulation. Extra structure has also been needed for guiding the linkage to becertain that both gates operate simultaneously. In instances of the kind referred to it has also been difficult to readily close the gates from a partially open position where only small quantities of material are to be discharged from the bucket at one location before it needs to be moved to a different location for a similar modest discharge.

Another element in the manipulation of prior art devices, which has caused concern, has been the possibility of inadvertent opening of the buckets by some agency pressing directly against one or another of the gates near the closing edge, causing the gates to be opened accidentally without the handle being manipulated.

It is'therefore among theobjects of the invention to provide a new and improved clam shell gate action for material handling buckets which employs a relatively minimum number of parts and which is simple and direct in its construction and is productive of considerable economy in design.

Another object of the invention is to provide a new and improved clam shell gate action which has built into it greatest mechanical advantage at the initial opening movement or final closing movement where greatest power is needed and wherein during final opening movement the gates may be swung rapidly open in order to positively dump all of the contents of the bucket.

. Still another object of the invention is to provide a new and improved clam shell gate action for devices such as material placing buckets in which a special lock is incorporated which gives positive assurance against the gates being inadvertently opened without manipulation of the regular opening mechanism.

Also included among the objects of the invention is to provide a new and improved clam shell gate action for simultaneously swinging a pair of clam shell gates to open position and subsequently from open to closed position wherein there is positive assurance of simultaneous and uniform action of both gates, such assurance being built into the linkage itself without their being need for additional guides for any of the working parts.

With these and other objects in view, the invention consists in the construction, arrangement and combination of the various parts of the device, whereby the ob- 'jects contemplated are attained, as hereinafter set forth, pointed out in the appended claims and illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a partial side elevational view of a material placement bucket showing the clam shell gates and the gate action linkage, the gates being shown in closed position.

FIG. 2 is a fragmentary side elevational view partially broken away showing the gates at an early stage of the opening movement.

FIG. 3 is a fragmentary side elevational view taken on the line 3-3 of FIG. 1.

FIG. 4 is a fragmentary cross-sectional view taken on the line 4-4 of FIG. 1.

FIG. 5 is a fragmentary longitudinal sectional view taken on the line 5-5 of FIG. 1.

FIG. 6 is a side elevational view of the gate action linkage set up to operatein a direction opposite from that of FIG. 1.

FIG. 7 is a side elevational view of the gate action equipped with a power actuator.

FIG. 8 is a side elevational view of the gate action with a modified form of stop. I

FIG. 9 is a fragmentary sectional view line 9-9 of FIG. 8.

In an embodiment of the invention chosen for the purpose of illustration there is shown a bucket indicated generally by the reference character 10 having a tapered lower portion 11 terminating in a vertical chute 12 at the bottom of which is an opening 13. A bale or sling (not shown) is normally attached at a supporting pivot 14 by means of which the bucket can be lifted and moved from place to place. For closing the opening 13 there is employed a pair of clam shell gates indicated respectively by the reference characters 15 taken on the and 16, these gates being substantially identical except for being mounted to swing in opposite directions. When the gates are closed, as shown in FIG. 1, respective edges 17 and 18 abut each other so that the gates are able to hold material such as concrete 19 in the bucket, but ready for deposit when called for.

The gate includes end plates 20 and 21, the end plate 20 being pivotally supported by a pivot pin 22, in the form of a bolt, bolted to a bracket 23 on a wall 24 of the chute 12. The other end plate 21 is similarly pivotally connected to a wall 25 at the opposite end.

Similarly one end plate 26 of the gate 16 is mounted on a pivot pin 27 on a portion of the bracket 23. End plate 28 at the opposite end of the gate 16 is pivotally mounted by means of the pivot pin 29 to a bracket 30 on the wall 25, this being the same bracket to which the end plate 21 of the gate 15 is also mounted. Arcuate plates 31 and 32 form bottoms respectively of the gates 15 and 16, the combined width of the arcuate plates when closed being in excess of the full width of the opening 13 at the bottom of the chute.

At one end of the gates 15 and 16 identified by the end plates 20 and 21 is a pair of actuator arms identified by the reference characters 35 and 36 respectively. The actuator arm 35 has a pivot connection 37 to the uppermost end of the end plate 20. The actuator arm 36 has a pivot connection 38 to the uppermost end of the end plate 26. Opposite ends of the actuator arms 35 and 36 have a pivot connection 39 to each other.

Similarly at opposite ends of the gates there is provided a pair of actuator arms, one arm 40 of which is shown in FIG. 3, the actuator arms last identified being the same in all respects as the actuator arms 35 and 36. For manipulating the actuator arms there is provided a handle 42 having one side extension 43 welded to the actuator arm 36 and another side extension 44 welded to the actuator arm 40. In closed position, as shown in FIG. I, the actuator arms 35 and 36 are moved to a position bearing against a stop lug 45 on the lower portion 11 of the bucket. A similar stop lug 46 is provided for the actuator arms at the corresponding end.

To make certain that the clam shell gates swing at similar rates and for similar distances there is provided at the end, visible in FIGS. 1 and 2, a synchronizer link 50. The link 50 has a pivot connection 51 to the end plate 20. At the other end the synchronizer link 50 is pivotally secured to the pivot connection 38 previously described my means of which it is attached to the end plate 26.

Similarly at the opposite ends of both gates there is a synchronizer link 52 which has a pivot connection 53 to the end plate 21 of the gate 15. A pivot connection 54 pivotally attaches the opposite end of the synchronizer link 52 to an end plate 55 of the gate 16. The pivot connection 54 is also the means by which the actuator arm 40 is attached to the end plate 55.

In operation it can be assumed that when the gates 15 and 16 are closed as shown in FIG. 1 the handle 42 is at its highest position and the junction of the links 35 and 36 abuts the stop lug 45. When the gates are to be opened the handle is moved in a downwardly direction from the solid line position of FIG. 1 toward the broken line position, the effect of which is to swing the pivot connection 39 downwardly which tends to draw the top ends of the end plates 20 and 26 toward each other simultaneously swinging the arcuate plates 31 and 32 away from each other, initially to a distance such, for example, as that shown in FIG. 2. The showing of FIG. 2 is a partially opening only in which the handle 42 is moved a relatively great distance but in which the edges 17 and 18 are moved apart only a small distance, The relative movements indicate the greater mechanical advantage by means of which an adequate amount of power is applied to the initial opening movement when the need for power is greatest. Should it be necessary to close the gates from this initially open position a similar great amount of power is available by lifting the handle 42 again to its uppermost position which causes the actuator arms to again swing upwardly to the position of FIG. 1 and close the gates. A second opening movement is accomplished similarly. On those occasions when the gates are to be swung wide open the handle is moved to the broken line position of FIG. 1. During this final movement the gates swing rapidly to their full wide open position as shown by their broken lines in FIG. 1. Contrarily, after dumping the full load from the bucket, when the gates are to be closed, initial movement of the handle upwardly, as shown in FIG. 1, pulls the gates rapidly from the broken line position toward each other during the first stages of the movement, this being followed by a slower movement to final closing position as the handle 42 is moved back to its initial position.

It can be noted from an examination of FIG. 4 that for a proper stabilized arrangement of actuator arms and the synchronizer link the actuator arm 36, for example, can be a double plate construction throughout the length and the actuator arm 35 bifurcated at its attachment to the end plate 20. The synchronizer link 50 is spaced clear of the arms by a suitably sized pivot connection so that the movement is clear.

Although the synchronizer link operates successfully when attached to the gates at respectively upper and lower sides of the respective gates, a structure of special simplicity is one where, as described, one end of the link is attached at the same pivot connection 38 where the respective arm 36 is attached. Under such circumstances the distance between the pivot pin 22 and pivot connection 51 is identical with respect to the distance between the pivot pin 22 and the pivot connection 37. These distances are then made equal to the distance between the pivot pin 27 on the end plate 26 and the pivot connection 38. Comparable distances are observed on the other end.

Automatic locking of the gates in closed position is accomplished by engagement of the actuator arms against the respective stop lugs. When this point of engagement is in over-center position as shown in FIG. 1, for example, it will be appreciated that there can be no movement of the gates and the edges 17 and 18 away from each other without the pivot connection 39 shifting from the position thereshown. While it is true that the shift in position of the pivot connection 39 could be up or down thus to permit the gates to swing toward open position, upward movement is prevented by engagement with the respective stop lug and movement downward is prevented because, as long as the handle 42 stays in its upward position, the actuator arms cannot move over-center downwardly. In the relationship described should any force be applied to either of the gates in an opening direction such movement is translated to a movement of the pivot connections 37 and 38 toward each other which would result in a tendency to cause the actuator arms 35 and 36 to tend to move toward each other and jackknife the pivot connection 39 upwardly. Since there is a positive resistance to such tendency the gates are therefore positively locked in closed position. The locking described, however, has no effect whatsoever on the ability of thehandle 42 to remove readily downwardly whereby to immediately and positively open the gates as a result of such normal opening action.

When the bucket capacity is relatively smaller than that contemplated by the bucket l0"ofFIG-. l a gate action such as that shown in FIG. 6 is acceptable. In this arrangement a handle, one side extension-60 of which is shown in FIG. 6', is attached to an actuator arm 35', namely, the actuator arm nearer the-side on which the handle is located. In order to depend upon downward movement of the handle to open the gates the actuator arms are arranged to jackknife in a direction opposite from that of FIG. 1, namely, to swing upwardly instead of downwardly. On this occasion a stop lug 45' is located below a pivot connection 39' interconnecting the actuator arm 35' and an opposite actuator arm 36'. The gates are similarly locked in closed position for this arrangement of parts. An advantage in the last described arrangement is in it being possible to make use of a handle somewhat shorter than the handle would have to be if connected to the actuator arm 36', resulting in a lesser mechanical advantage but under circumstances where such lesser mechanical advantage can be tolerated.

The actuator arms 35 and 36 are of such construction and relationship that the gates can readily be arranged for operation for a power actuated device such, for example, as a hydraulic or pneumatic cylinder 60' as shown in FIG. 7. The cylinder is provided with an upper mounting bracket 61 by means of which it is pivotally fastened to a lug 62 on the lower portion 1 1 of the bucket. A piston 63 extending from the cylinder is pivotally secured to the pivot connection 39 where the actuator arms 35 and 36 are interconnected.

By actuation of the cylinder, which is a substantially conventional type power cylinder, the piston may be extended downwardly to the broken line position shown in FIG. 7 to open the gates 21 and 26. When the cylinder is a double acting device operation of the cylinder in a contrary direction adapted to withdraw the piston 63 from the broken line position to the solid line position of FIG. 7 closes the gates. Closing, of course, may be accomplished from any open position of the gates and, moreover, the gates can be swung from a partially open position to a wider open position or in the reverse throughout any partial or full closing I operation depending upon manipulation of the cylinder. Further still, by having the piston 63 bottom in a position wherein the pivot connection 39 is slightly over-center upwardly relative to the pivot connections 37 and 38 the gates are effectively locked in a closed position against the inadvertent opening by means other than manipulation of the cylinder.

As shown in FIGS. 8 and 9 a stop of a slightly different type is employed with respective actuator arms distance from the pivotal mount to the pivotal connecand 66. As shown a narrow section 65 of the actuator arm 65 is pivotally attached to opposite side portions 66' of the actuator arm 66 by means of a pivot connection 67. A stop 68 is welded to the actuator arm 66 below and adjacent tothe pivot connection 67, a portion of the stop 68 extending beneath the actuator arm 65. Again, as previously noted, engagement of the stop 68 with the actuator arm 65 may be slightly overcenter in an upward direction thereby to securely lock the gates in closed position.

To further assist in manipulating the gates an extension 69 is provided on the actuator arm 66, the extension terminating in a hook 70. A spring 71 has one end engaged in a book and the opposite end engaged with a spring connection 72 on the outer edge of the arcuate plate 32. y

A second spring 73 has one end in engagement with the pivot connection22 and the opposite end in engagement with a spring connection 74 on the end plate 26. These springs 71 and 73 are placed under increased tension when the gates are opened by manipulation of the handle 42 whereby when the handle is moved in a direction closing the gates, movement will be assisted by spring action. The spring 71, however, acts in a special. fashion during final full opening movement. In that phase of the opening cycle the spring 71 reverses its action and serves to assist the final opening movement, due to a shift of the relative positions of pivot points and locations of the spring ends.

Having described the invention, what is claimed as new in support of Letters Patent is:

1. An operating mechanism for a clam shell discharge on a material placing container having a bottom discharge opening, said mechanism comprising a pair of oppositely acting gate members each having end plates and pivotal mounts mounting said end plates on the container, said pivotal mounts being located intermediate top and bottom of the respective end plate, a pair of actuator arms extending between said gates, said arms being pivotally connected together at adjacent ends, the other ends of said arms having a pivotal connection secured one to each gate, the pivotal connection being made to the respective gate at a location intermediate the pivotal mount and the top of the gate, and a synchronizing link interconnecting said gates, one end of said link having a pivotal attachment on the upper side of the pivotal mount, the other end of the link having a pivotal attachment to the adjacent end plate of the other gate at a location below the pivotal mount.

2. An operating mechanism as in claim 1 wherein one pivotal attachment of said link is to the pivotal connection of one of said arms on the end plate of one gate and the pivotal attachment of the other end of the link is at a location intermediate the pivotal mount and the bottom of the plate.

3. An operating mechanism as in claim 2 wherein the tion is equal to the distance from the pivotal mount to F the pivotal attachment, whereby the gates are opened and closed simultaneously.

4. An operating mechanism as in claim 1 wherein there is a pair of actuator arms and related synchronizing links at each end of the respective gates.

5. An operating mechanism as in claim 1 wherein when the gates are in closed positions the actuator arms are substantially in longitudinal alignment.

6. An operating mechanism as in claim 1 wherein there is a stop on the container for said arms, said stop being at a location wherein when the adjacent ends of the arms are in engagement with the stop and the gates are closed, the arms are slightly out of longitudinal alignment in a direction away from an opening direction, whereby to lock the gates in closed position against inadvertent opening of said gates by an opening force applied to one or both of said gates.

7. An operating mechanism as in claim 1 wherein there is a manually operated handle having one end attached to one of said pair of actuator arms, the other end of said handle being located on a side of the container opposite from said one actuator arm.

8. An operating mechanism as in claim 1. wherein there is a manually operated handle having one end attached to one of said pair of actuator arms, the other end of said handle being located on the same side of said container as said one operating arm.

9. An operating mechanism as in claim 1 wherein there is a stop on one of said arms in a position overlying the other of said arms, said stop having an abutting engagement with the other of said arms when said arms are slightly out of horizontal alignment.

[0. An operating mechanism as in claim 1 wherein there is an extension on one of said actuator arms on the opposite side of said pivotal connection and a spring having one end connected to the extension and the other end connected to the adjacent gate whereby to bias said gate toward closed positions.

11. An operating mechanism as in claim 1 wherein there is a spring having one end connected to one of said gates and the other end connected to the other of said gates.

12. An operating mechanism as in claim 1 wherein there is an actuator ram comprising a piston member and a cylinder member, the longitudinal axis of said ram extending vertically through the pivotal connection between said actuator arms, one of said members being attached to said container and the other of said members being in engagement with said actuator arms. 

1. An operating mechanism for a clam shell discharge on a material placing container having a bottom discharge opening, said mechanism comprising a pair of oppositely acting gate members each having end plates and pivotal mounts mounting said end plates on the container, said pivotal mounts being located intermediate top and bottom of the respective end plate, a pair of actuator arms extending between said gates, said arms being Pivotally connected together at adjacent ends, the other ends of said arms having a pivotal connection secured one to each gate, the pivotal connection being made to the respective gate at a location intermediate the pivotal mount and the top of the gate, and a synchronizing link interconnecting said gates, one end of said link having a pivotal attachment on the upper side of the pivotal mount, the other end of the link having a pivotal attachment to the adjacent end plate of the other gate at a location below the pivotal mount.
 1. An operating mechanism for a clam shell discharge on a material placing container having a bottom discharge opening, said mechanism comprising a pair of oppositely acting gate members each having end plates and pivotal mounts mounting said end plates on the container, said pivotal mounts being located intermediate top and bottom of the respective end plate, a pair of actuator arms extending between said gates, said arms being Pivotally connected together at adjacent ends, the other ends of said arms having a pivotal connection secured one to each gate, the pivotal connection being made to the respective gate at a location intermediate the pivotal mount and the top of the gate, and a synchronizing link interconnecting said gates, one end of said link having a pivotal attachment on the upper side of the pivotal mount, the other end of the link having a pivotal attachment to the adjacent end plate of the other gate at a location below the pivotal mount.
 2. An operating mechanism as in claim 1 wherein one pivotal attachment of said link is to the pivotal connection of one of said arms on the end plate of one gate and the pivotal attachment of the other end of the link is at a location intermediate the pivotal mount and the bottom of the plate.
 3. An operating mechanism as in claim 2 wherein the distance from the pivotal mount to the pivotal connection is equal to the distance from the pivotal mount to the pivotal attachment, whereby the gates are opened and closed simultaneously.
 4. An operating mechanism as in claim 1 wherein there is a pair of actuator arms and related synchronizing links at each end of the respective gates.
 5. An operating mechanism as in claim 1 wherein when the gates are in closed positions the actuator arms are substantially in longitudinal alignment.
 6. An operating mechanism as in claim 1 wherein there is a stop on the container for said arms, said stop being at a location wherein when the adjacent ends of the arms are in engagement with the stop and the gates are closed, the arms are slightly out of longitudinal alignment in a direction away from an opening direction, whereby to lock the gates in closed position against inadvertent opening of said gates by an opening force applied to one or both of said gates.
 7. An operating mechanism as in claim 1 wherein there is a manually operated handle having one end attached to one of said pair of actuator arms, the other end of said handle being located on a side of the container opposite from said one actuator arm.
 8. An operating mechanism as in claim 1 wherein there is a manually operated handle having one end attached to one of said pair of actuator arms, the other end of said handle being located on the same side of said container as said one operating arm.
 9. An operating mechanism as in claim 1 wherein there is a stop on one of said arms in a position overlying the other of said arms, said stop having an abutting engagement with the other of said arms when said arms are slightly out of horizontal alignment.
 10. An operating mechanism as in claim 1 wherein there is an extension on one of said actuator arms on the opposite side of said pivotal connection and a spring having one end connected to the extension and the other end connected to the adjacent gate whereby to bias said gate toward closed positions.
 11. An operating mechanism as in claim 1 wherein there is a spring having one end connected to one of said gates and the other end connected to the other of said gates. 